Retracts and homotopies for multi-maps
We show that every retral continuum with the fixed point property is locally connected. It follows that an indecomposable continuum with the fixed point property is not a retract of a topological group.
Let , and denote the -groups of integer-valued, rational-valued and real-valued continuous functions on a topological space , respectively. Characterizations are given for the extensions to be rigid, major, and dense.
We prove that a Hausdorff space is locally compact if and only if its topology coincides with the weak topology induced by . It is shown that for a Hausdorff space , there exists a locally compact Hausdorff space such that . It is also shown that for locally compact spaces and , if and only if . Prime ideals in are uniquely represented by a class of prime ideals in . -compact spaces are introduced and it turns out that a locally compact space is -compact if and only if every...